Volatile memory, such as the dynamic random access memory (DRAM) most commonly found in personal computers, is advantageous because if its increased memory density over other, nonvolatile storage. Since volatile memory loses its content when power is cut off, it is generally not useful for long-term storage but, instead, is generally used for temporary storage of data while a computer is running.
A typical DRAM consists of an array of transistors or switches coupled to capacitors, where the transistors are used to switch a capacitor into or out of a circuit for reading or writing a value stored in the capacitive element. These storage bits are typically arranged in an array of rows and columns, and are accessed by specifying a memory address that contains or is decoded to find the row and column of the memory bit to be accessed.